Organisms can have positive or negative impacts on the ecosystem they live in. The cane toad, or Rhinella marina, was introduced to the Hawaiian Islands in 1932 by sugar cane farmers. Farmers released the toads in their crops to help control pests that were damaging the sugar cane. The cane toad has few natural predators, as it secretes a poisonous toxin from its skin that deters larger organisms from eating it. As a result, the cane toad population thrived and grew to number hundreds of thousands by 1935. Brown toad in grass.

Photo by Patrick Gijsbers

Which role does the cane toad play in the Hawaiian Islands?

native species
invasive species
uncontrolled species
endangered species

Taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? view available hint(s)taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? the enzyme will not work on human dna. nothing should be altered. the ph should be decreased. the temperature should be raised.

To test the responsiveness of the kidneys, scientists have designed an experiment tracking urine output of people during a normal day, while regulating the in-take of water by mouth. what would be an appropriate hypothesis for this experiment?

What determines whether a particular cell is able to respond to a hormone?